Heat temperature gradient heat exchanger

Abstract

A heat exchanger assembly includes an outer manifold defining an outer cavity. An inner cavity is defined by an inner shell supported within the outer manifold and at least partially surrounded by the outer cavity. The inner shell includes a plurality of impingement openings for directing airflow into the inner cavity. An inner manifold is supported within the inner cavity. The inner manifold is exposed to impingement airflow through the plurality of impingement openings in the inner shell. The inner manifold includes a plurality of flow passages and at least one insulator pocket substantially aligned with the plurality of flow passages. A cooled cooling air system for a gas turbine engine and a gas turbine engine assembly are also disclosed.

What is claimed is: 
     
       1. A heat exchanger assembly comprising:
 an outer manifold defining an outer cavity 
 an inner cavity defined by an inner shell supported within the outer manifold and at least partially surrounded by the outer cavity, the inner shell including a plurality of impingement openings for directing airflow into the inner cavity; and 
 an inner manifold supported within the inner cavity, wherein the inner manifold is exposed to impingement airflow through the plurality of impingement openings in the inner shell, the inner manifold including a plurality of flow passages and at least one insulator pocket substantially aligned with the plurality of flow passages and closed to exposure to airflow. 
 
     
     
       2. The heat exchanger assembly as recited in  claim 1 , wherein the inner shell includes at least two fingers supporting the inner manifold, the at least two fingers are compliant to accommodate thermal expansion of the inner manifold. 
     
     
       3. The heat exchanger assembly as recited in  claim 2 , including at least one opening for airflow in each of the at least two fingers. 
     
     
       4. The heat exchanger assembly as recited in  claim 1 , wherein the outer manifold defines an inlet into the outer cavity, and the inner cavity is open at opposing first and second ends transverse to the direction of impingement flow. 
     
     
       5. The heat exchanger assembly as recited in  claim 1 , including at least two insulator pockets disposed between each of the plurality of flow passages. 
     
     
       6. The heat exchanger assembly as recited in  claim 1 , wherein each of the plurality of passages includes a length substantially aligned with cooling airflow from the plurality of impingement openings, the length of each of the plurality of passages is greater than a width transverse to the direction of the cooling airflow from the plurality of impingement openings. 
     
     
       7. The heat exchanger assembly as recited in  claim 6 , wherein each of the plurality of passages includes a midpoint between a first end and a second end and a width at the midpoint is greater than a width at each of the first end and the second end. 
     
     
       8. The heat exchanger assembly as recited in  claim 7 , wherein an outer surface of the inner manifold includes peaks corresponding to the first end and the second end separated by valleys. 
     
     
       9. A cooled cooling air system for a gas turbine engine comprising:
 a first source of airflow at a first pressure and temperature; 
 a second source of airflow at a second pressure and temperature, the second temperature and pressure less than the first temperature and pressure; and 
 a heat exchanger assembly including:
 an outer manifold defining an outer cavity and a cold inlet in communication with airflow from the second source; 
 an inner shell defining an inner cavity, the inner shell supported within the outer manifold and at least partially surrounded by the outer cavity, the inner shell including a plurality of impingement openings for directing airflow from the outer manifold into the inner cavity; and 
 an inner manifold supported within the inner cavity and a hot inlet in communication with airflow from the first source, wherein the inner manifold is exposed to impingement airflow through the plurality of impingement openings in the inner shell, the inner manifold including a plurality of flow passages and at least one insulator pocket substantially aligned with the plurality of flow passages and closed to exposure to airflow. 
 
 
     
     
       10. The cooled cooling air system as recited in  claim 9 , wherein the inner shell includes at least two fingers supporting the inner manifold, the at least two fingers are compliant to accommodate thermal expansion of the inner manifold. 
     
     
       11. The cooled cooling air system as recited in  claim 9 , wherein the inner cavity is open at opposing first and second ends transverse to a direction of impingement flow. 
     
     
       12. The cooled cooling air system as recited in  claim 9 , wherein each of the plurality of passages includes a length substantially aligned with cooling airflow from the plurality of impingement openings, the length of each of the plurality of passages is greater than a width transverse to the direction of the cooling airflow from the plurality of impingement openings. 
     
     
       13. A gas turbine engine assembly comprising:
 a compressor section including a bleed air opening for a first source of airflow at a first pressure and first temperature; 
 a second source of airflow at a second pressure and a second temperature; 
 a heat exchanger assembly including;
 an outer manifold defining an outer cavity and a cold inlet in communication with airflow from the second source, 
 an inner shell defining an inner cavity, the inner shell supported within the outer manifold and at least partially surrounded by the outer cavity, the inner shell including a plurality of impingement openings for directing airflow from the outer manifold into the inner cavity; and 
 an inner manifold supported within the inner cavity and a hot inlet in communication with airflow from the first source, wherein the inner manifold is exposed to impingement airflow through the plurality of impingement openings in the inner shell, the inner manifold including a plurality of flow passages and at least one insulator pocket substantially aligned with the plurality of flow passages and closed to exposure to airflow; and 
 a turbine section including at least one cooling air passage receiving cooled airflow from an outlet of the inner manifold. 
 
 
     
     
       14. The gas turbine engine assembly as recited in  claim 13 , wherein the inner shell includes at least two fingers supporting the inner manifold, the at least two fingers are compliant to accommodate thermal expansion of the inner manifold. 
     
     
       15. The gas turbine engine assembly as recited in  claim 13 , wherein the inner cavity is open at opposing first and second ends transverse to a direction of impingement flow. 
     
     
       16. The gas turbine engine assembly as recited in  claim 13 , wherein each of the plurality of passages includes a length substantially aligned with cooling airflow from the plurality of impingement openings, the length of each of the plurality of passages is greater than a width transverse to the direction of the cooling airflow from the plurality of impingement openings.